If your first flight is delayed and you are traveling on a single ticket with British Airways, the airline is legally obligated to take care of you under UK261/2004 regulations. First, BA will automatically rebook you on the next available flight to your destination. If that flight is the next day, they must provide complimentary hotel accommodation, transportation, and meal vouchers. If the delay is more than 5 hours and you no longer wish to travel, you are entitled to a full refund. Importantly, if the delay at your final destination is more than 3 hours and the cause was within the airline's control (e.g., a technical fault, not weather), you may be entitled to fixed-sum compensation ranging from £220 to £520. However, if you booked your flights as two separate tickets (not on one PNR), British Airways has no legal obligation to rebook you or provide assistance; they would treat you as a "no-show" for the second flight. In 2026, BA has also introduced "automated rebooking" through their mobile app, allowing you to choose your new flight options and download new boarding passes instantly while still in the air or upon landing.